"Are we barking up the wrong tree? Too much emphasis on Cutibacterium acnes and ignoring other pathogens"- a study based on next-generation sequencing of normal and diseased discs.

BACKGROUND: The majority of literature on bacterial flora in the disc stands disadvantaged in utilizing traditional culture methods and targeting a single bacterium, Cutibacterium acnes. PURPOSE: Our objective was to document the diversity in the bacterial flora between normal and degenerated discs for shortlisting potential pathogens using next-generation genomic tools. STUDY DESIGN: Experimental case-control study. METHODS: Researchers employed 16S metagenome sequencing to profile bacterial diversity in magnetic resonance imaging normal healthy discs from brain-dead organ voluntary donors (n=20) and 40 degenerated disc samples harvested during surgery (Modic [MC]=20 and non-Modic [NMC]=20). The V3-V4 region was amplified using universal bacterial primers 341F and 806R, and the libraries were sequenced using Illumina NovoSeq 6000 platform. Statistical significance was set at bacteria with a minimum of 100 operational taxonomic unit (OTU) and present in at least 70% of the samples. The quality check-filtered reads were processed using the QIIME-2 pipeline. The OTU clustering and taxonomic classification were carried out for the merged reads using the Greengenes/SILVA reference database. Validation was done by identification of bacterial metabolites in samples using the liquid chromatography-mass spectrometry approach. RESULTS: Abundant bacteria differing widely in diversity, as evidenced by Alfa and Beta diversity analysis, were present in all control and degenerative samples. The number of bacterial genera was 27 (14-gram-positive: 13-gram-negative) in the control group, 23 (10-gram-positive: 11-gram-negative) in the Modic group, and 16 (11-gram-positive: 5-gram-negative) in the non-Modic group. In the Modic group, gram-negative bacteria OTUs were found to be predominant (more than 50% of the total bacteria identified), whereas in control and non-Modic groups the OTUs of gram-positive bacteria were predominant. Species-level analysis revealed an abundance of opportunistic gram-negative pathogens like Pseudomonas aeruginosa, Sphingomonos paucibacillus, and Ochrobactrum quorumnocens in the discs with Modic changes, more than in non-Modic discs. The presence of bacterial metabolites and quorum-sensing molecules like N-decanoyl-L-homoserine lactone, 6-hydroxynicotinic acid, 2-aminoacetophenone, 4-hydroxy-3-polyprenylbenzoate, PE (16:1(9Z)/18:0) and phthalic acid validated the colonization and cell-cell communication of bacteria in disc ruling out contamination theory. Cutibacterium acnes was not the predominant bacteria in any of the three groups of discs and in fact was in the 16th position in the order of abundance in the control discs (0.72%), seventh position in the Modic discs (1.41%), and 12th position (0.53%) in the non-Modic discs. CONCLUSION: This study identified a predominance of gram-negative bacteria in degenerated discs and highlights that Cutibacterium acnes may not be the only degeneration-causing bacteria. This may be attributed to the environment, diet, and lifestyle habits of the sample population. Though the study does not reveal the exact pathogen, it may pave the way for future studies on the subject. CLINICAL SIGNIFICANCE: These findings invite further investigation into causal relationships of bacterial profile with disc degeneration phenotypes as well as phenotype-driven clinical treatment protocols.

A retrospective analysis to estimate trough concentrations of teicoplanin in patients with suspected or documented Gram-positive infections

Abstract Teicoplanin is a glycopeptide antibiotic commonly used to treat Gram-positive bacterial infections in the clinic. The aim of this study was to provide a therapeutic reference for the clinical application and dosage regimen adjustment of teicoplanin by identifying factors associated with its plasma trough concentration (Ctrough). A retrospective study was performed on patients with suspected or documented Gram-positive infections who were hospitalized from November 2017 to January 2020 and treated with teicoplanin while undergoing routine therapeutic drug monitoring (TDM). A total of 112 Ctrough trough measurements were obtained from 72 patients were included in this study. SPSS software was used for correlation analysis and receiver operator characteristic curve (ROC) analysis. The Ctrough for teicoplanin showed statistically significant relationships (P<0.05) with PLT, Scr, CLcr, eGFR, BUN and Cys-C. ROC curve analysis revealed that CLcr and eGFR were more sensitive and specific for Ctrough compared to the other factors. These findings should be considered in the clinical application of teicoplanin and for its dosage adjustment.

Different responses of cervical intervertebral disc caused by low and high virulence bacterial infection: a comparative study in rats.

The aims of this study were to investigate the outcomes of low- and high-virulence bacterial cervical intervertebral discs (IVDs) infection and its association with cervical IVDs degeneration in rats. A total of 75 clean grade male rats were used to establish the corresponding animal models of low and high virulent bacterial cervical disc infection via an anterior cervical approach, with injection of Propionibacterium acnes (P. acnes) and Staphylococcus epidermidis (S. epidermidis) with a 29 G needle to cervical IVDs. Specimens were collected for evaluation of Blood routine (Blood-RT), histological staining, and gene expression assays after a magnetic resonance imaging (MRI) scan. There were no statistical differences in all groups in white blood cells (WBC) at 2 and 6 weeks postoperatively (P = 0.136). The highest percentage of neutrophils was found in the S. epidermidis group at 2 weeks postoperatively (P = 0.043). MRI and histology showed that at 6 weeks postoperatively, the puncture group and P. acnes group had similar disc degeneration. In the S. epidermidis group, the disc and subchondral bone structure had been destroyed and bony fusion had occurred after the discitis. The upregulation of pro-inflammatory factor expression had the strongest effect of S. epidermidis on the early stage, while the upregulation in the puncture and P. acnes groups was more persistent. P. acnes infection of the cervical IVDs can lead to degenerative changes, whereas S. epidermidis infection leads to the manifestation of septic discitis. The correlation between P. acnes infection and cervical IVDs degeneration found in clinical studies was confirmed.

High frequency of enterotoxigenic Bacteroides fragilis and Enterococcus faecalis in the paraffin-embedded tissues of Iranian colorectal cancer patients.

BACKGROUND: The association between specific bacteria and colorectal cancer (CRC) has been proposed. Only a few studies have, however, investigated this relationship directly in colorectal tissue with conflicting results. So, we aimed to quantitate Streptococcus gallolyticus, Fusobacterium spp, Enterococcus faecalis and enterotoxigenic Bacteroides fragilis (ETBF) in formalin-fixed and paraffin-embedded (FFPE) colorectal tissue samples of Iranian CRC patients and healthy controls. METHODS: A total of 80 FFPE colorectal tissue samples of CRC patients (n = 40) and healthy controls (n = 40) were investigated for the presence and copy number of above bacterial species using quantitative PCR. Relative quantification was determined using ΔΔCT method and expressed as relative fold difference compared to reference gene. RESULTS: Relative abundance and copy number of E. faecalis and ETBF were significantly higher in CRC samples compared to control group. E. faecalis was more prevalent than ETBF in tumor samples. Frequency of ETBF and E. faecalis in late stages (III/IV) of cancer was significantly higher than early stages (I/II). We did not detect a significant difference in abundance of S. gallolyticus and Fusobacterium spp between two groups. CONCLUSION: Our study revealed the higher concentration of E. faecalis and ETBF in FFPE samples of CRC patients than controls. However, additional investigations on fecal and fresh colorectal cancer tissue samples are required to substantiate this correlation.

Rapidly fatal infection with Bacillus cereus/thuringiensis: genome assembly of the responsible pathogen and consideration of possibly contributing toxins.

Bloodstream infection with Bacillus cereus/thuringiensis can be life threatening, particularly in patients who are severely immunocompromised. In this report we describe a case that progressed from asymptomatic to fatal over approximately 5 hours despite extensive resuscitation efforts. We identify the pathogen and assemble its genome, in which we find genes for toxins that may have contributed to the precipitous demise. In the context of this and other cases we discuss the possible indication for rapid appropriate antibiotic administration and potentially antitoxin treatment or toxin removal in fulminant illness in immunocompromised patients.

Clinical Characteristics of Patients with Micrococcus luteus Bloodstream Infection in a Chinese Tertiary-Care Hospital.

Few pieces of research have focused on Micrococcus luteus bloodstream infection (BSI) because of its low incidence; hence data is needed to illustrate this uncommon infection. This study aimed to explore the clinical characteristics of patients with M. luteus BSI. From January 2010 to December 2019, inpatients that met the criteria for M. luteus BSI were included in this study. Data was collected by reviewing electronic records. Ninety-seven patients were enrolled in this study. Sixty-three percent of the patients have a higher neutrophil percentage (NEUT%). The average blood C-reactive protein (CRP) concentration was 5.5 ± 6.4 mg/dl. 48.5% of the patients had malignancy, and 40.2% underwent invasive surgeries. Linezolid was found to have the largest average diameter of the inhibition zone (36 mm), while erythromycin was found to have the smallest average zone diameter (15 mm). However, some M. luteus strains had a potentially broad antimicrobial resistance spectrum. Cephalosporins (59.2%) and quinolones (21.4%) were the most commonly used antibiotics for empirical therapies. In conclusion, M. luteus BSI mainly happens in immunocompromised patients or those with former invasive surgeries or indwelling catheters. M. luteus strains are less responsive to erythromycin. Cephalosporins and quinolones are effective empirical antibiotics for M. luteus BSI; however, vancomycin and teicoplanin should be considered for potentially broadly drug-resistant M. luteus strains.

A mouse model displays host and bacterial strain differences in Aerococcus urinae urinary tract infection.

In recent years, the clinical significance of Aerococcus urinae has been increasingly recognized. A. urinae has been implicated in cases of urinary tract infection (UTI; acute cystitis and pyelonephritis) in both male and female patients, ranging from children to older adults. Aerococcus urinae can also be invasive, causing urosepsis, endocarditis, and musculoskeletal infections. Mechanisms of pathogenesis in A. urinae infections are poorly understood, largely due to the lack of an animal model system. In response to this gap, we developed a model of A. urinae urinary tract infection in mice. We compared A. urinae UTI in female C3H/HeN and C57BL/6 mice and compared four clinical isolates of A. urinae isolated from patients with UTI, urgency urinary incontinence, and overactive bladder. Our data demonstrate that host genetic background modulates A. urinae UTI. Female C57BL/6 female mice rapidly cleared the infection. Female C3H/HeN mice, which have inherent vesicoureteral reflux that flushes urine from the bladder up into the kidneys, were susceptible to prolonged bacteriuria. This result is consistent with the fact that A. urinae infections most frequently occur in patients with underlying urinary tract abnormalities or disorders that make them susceptible to bacterial infection. Unlike uropathogens such as E. coli, which cause infection and inflammation both of the bladder and kidneys in C3H/HeN mice, A. urinae displayed tropism for the kidney, persisting in kidney tissue even after clearance of bacteria from the bladder. Aerococcus urinae strains from different genetic clades displayed varying propensities to cause persistent kidney infection. Aerococcus urinae infected kidneys displayed histological inflammation, neutrophil recruitment and increased pro-inflammatory cytokines. These results set the stage for future research that interrogates host-pathogen interactions between A. urinae and the urinary tract.

Molecular Mechanisms of Mast Cell Activation by Cholesterol-Dependent Cytolysins.

Mast cells are potent immune sensors of the tissue microenvironment. Within seconds of activation, they release various preformed biologically active products and initiate the process of de novo synthesis of cytokines, chemokines, and other inflammatory mediators. This process is regulated at multiple levels. Besides the extensively studied IgE and IgG receptors, toll-like receptors, MRGPR, and other protein receptor signaling pathways, there is a critical activation pathway based on cholesterol-dependent, pore-forming cytolytic exotoxins produced by Gram-positive bacterial pathogens. This pathway is initiated by binding the exotoxins to the cholesterol-rich membrane, followed by their dimerization, multimerization, pre-pore formation, and pore formation. At low sublytic concentrations, the exotoxins induce mast cell activation, including degranulation, intracellular calcium concentration changes, and transcriptional activation, resulting in production of cytokines and other inflammatory mediators. Higher toxin concentrations lead to cell death. Similar activation events are observed when mast cells are exposed to sublytic concentrations of saponins or some other compounds interfering with the membrane integrity. We review the molecular mechanisms of mast cell activation by pore-forming bacterial exotoxins, and other compounds inducing cholesterol-dependent plasma membrane perturbations. We discuss the importance of these signaling pathways in innate and acquired immunity.

Novel genomic islands and a new vanD-subtype in the first sporadic VanD-type vancomycin resistant enterococci in Norway.

BACKGROUND: Vancomycin-resistant enterococci (VRE) represent several types of transferable vancomycin resistance gene clusters. The vanD type, associated with moderate to high level vancomycin resistance, has only sporadically been described in clinical isolates. The aim of this study was to perform a genetic characterization of the first VanD-type VRE strains detected in Norway. METHODS: The VanD-type VRE-strains (n = 6) from two patient cases were examined by antimicrobial susceptibility testing and whole genome sequencing (WGS) to uncover Van-phenotype, strain phylogeny, the vanD gene clusters, and their genetic surroundings. The putative transferability of vanD was examined by circularization PCR and filter mating. RESULTS: The VanD-type Enterococcus faecium (n = 4) and Enterococcus casseliflavus (n = 2) strains recovered from two cases (A and B), expressed moderate to high level vancomycin resistance (MIC 64->256 mg/L) and various levels of teicoplanin susceptibility (MIC 2->256 mg/L). WGS analyses revealed phylogenetically different E. faecium strains (A1, A2, and A3 of case A and B1 from case B) as well as vanD gene clusters located on different novel genomic islands (GIs). The E. casseliflavus strains (B2 and B3 of case B) were not clonally related, but harbored nearly identical novel GIs. The vanD cluster of case B strains represents a novel vanD-subtype. All the vanD-GIs were integrated at the same chromosomal site and contained genes consistent with a Clostridiales origin. Circular forms of the vanD-GIs were detected in all strains except B1. Transfer of vanD to an E. faecium recipient was unsuccessful. CONCLUSIONS: We describe the first VanD-type E. casseliflavus strains, a novel vanD-subtype, and three novel vanD-GIs with a genetic content consistent with a Clostridiales order origin. Despite temporal occurrence, case A and B E. faecium strains were phylogenetically diverse and harbored different vanD subtypes and vanD-GIs.

Intravitreal injection of povidone-iodine for the treatment of vancomycin-resistant Enterococcus faecalis endophthalmitis in rabbit eyes.

The aim of this study was to investigate the efficacy of intravitreal povidone-iodine (PI) in the treatment of vancomycin-resistant Enterococcus faecalis (VRE) endophthalmitis. Fifty New Zealand white rabbits were divided into 5 groups (n = 10 in each group). After the induction of endophthalmitis using VRE (minimum inhibitory concentration [MIC] ≥ 40 µg/mL) in the right eye, Group A, B, C, and D received intravitreal injections of 0.1% PI, 0.3% PI, 0.05% vancomycin, and 0.5% vancomycin, respectively. Eyes in Group E were used as controls. Fundus photography, vitreous culture, electroretinography (ERG), and histologic examinations of the retina were conducted on day 14. A marked improvement in endophthalmitis was observed in Group A, B, C and D, compared to Group E. Fundus photographs showed mild vitreous opacities in Group A and B, and moderate vitreous opacity in Group C. All eyes in Group D had a clear vitreous. In vitreous culture, bacterial growth was found in 6 eyes (100, 200, 200, 400, 500, and 500 colony-forming units) in Group C, but not in Groups A, B, or D. ERG and histological examination also indicated intraocular damage in Group C. Our results show that intravitreal injection of PI, even at low concentrations, was effective for treatment of VRE endophthalmitis, although some vitreous opacity remained. Intravitreal vancomycin injection was also useful to treat resistant strains, if used at a higher concentration within the safety threshold.

Florid Bacillus cereus Infection of the Placenta Associated With Intrauterine Fetal Demise.

Bacillus cereus is a gram-positive, rod-shaped bacterium that is commonly implicated in foodborne illness but has also become increasingly recognized as a source of serious non-gastrointestinal infections, including sepsis, meningitis, and pneumonia. Non-gastrointestinal B. cereus infections have been identified in children, especially in neonates; however, there are no previously described cases of fetal demise associated with B. cereus placental infection. We present a case of acute chorioamnionitis-related intrauterine fetal demise of twin A at 17 weeks gestation, noted two days after selective termination of twin B. Histological examination revealed numerous gram-positive bacilli in placental tissue, as well as fetal vasculature, in the setting of severe acute necrotizing chorioamnionitis and subchorionitis, intervillous abscesses, acute villitis, and peripheral acute funisitis. Cultures of maternal blood and placental tissue both yielded growth of B. cereus. This case underscores the importance of B. cereus as a human pathogen, and specifically demonstrates its potential as an agent of severe intraamniotic and placental infection with poor outcomes for the fetus.

Quantifying acquisition and transmission of Enterococcus faecium using genomic surveillance.

Nosocomial acquisition and transmission of vancomycin-resistant Enterococcus faecium (VREfm) is the driver for E. faecium carriage in hospitalized patients, which, in turn, is a risk factor for invasive infection in immunocompromised patients. In the present study, we provide a comprehensive picture of E. faecium transmission in an entire sampled patient population using a sequence-driven approach. We prospectively identified and followed 149 haematology patients admitted to a hospital in England for 6 months. Patient stools (n = 376) and environmental swabs (n = 922) were taken at intervals and cultured for E. faecium. We sequenced 1,560 isolates (1,001 stool, 559 environment) and focused our genomic analyses on 1,477 isolates (95%) in the hospital-adapted clade A1. Of 101 patients who provided two or more stool samples, 40 (40%) developed E. faecium carriage after admission based on culture, compared with 64 patients (63%) based on genomic analysis (73% VREfm). Half of 922 environmental swabs (447, 48%) were positive for VREfm. Network analysis showed that, of 111 patients positive for the A1 clade, 67 had strong epidemiological and genomic links with at least one other patient and/or their direct environment, supporting nosocomial transmission. Six patients (3.4%) developed an invasive E. faecium infection from their own gut-colonizing strain, which was preceded by nosocomial acquisition of the infecting isolate in half of these. Two informatics approaches (subtype categorization to define phylogenetic clusters and the development of an SNP cut-off for transmission) were central to our analyses, both of which will inform the future translation of E. faecium sequencing into routine outbreak detection and investigation. In conclusion, we showed that carriage and environmental contamination by the hospital-adapted E. faecium lineage were hyperendemic in our study population and that improved infection control measures will be needed to reduce hospital acquisition rates.

Cardiac Microlesions Form During Severe Bacteremic Enterococcus faecalis Infection.

Enterococcus  faecalis is a significant cause of hospital-acquired bacteremia. Herein, the discovery is reported that cardiac microlesions form during severe bacteremic E. faecalis infection in mice. The cardiac microlesions were identical in appearance to those formed by Streptococcus pneumoniae during invasive pneumococcal disease. However, E. faecalis does not encode the virulence determinants implicated in pneumococcal microlesion formation. Rather, disulfide bond forming protein A (DsbA) was found to be required for E. faecalis virulence in a Caenorhabditis elegans model and was necessary for efficient cardiac microlesion formation. Furthermore, E. faecalis promoted cardiomyocyte apoptotic and necroptotic cell death at sites of microlesion formation. Additionally, loss of DsbA caused an increase in proinflammatory cytokines, unlike the wild-type strain, which suppressed the immune response. In conclusion, we establish that E. faecalis is capable of forming cardiac microlesions and identify features of both the bacterium and the host response that are mechanistically involved.

Insights into Peptide Mediated Antibiofilm Treatment in Chronic Wound: A Bench to Bedside Approach.

Chronic wound biofilm infections are a threat to the population with respect to morbidity and mortality. The presence of multidrug-resistant bacterial pathogens in chronic wound renders the action of antibiotics and antibiofilm agents difficult. Therefore an alternative therapy is essential for reducing bacterial biofilm burden. In this scenario, the peptide-based antibiofilm therapy for chronic wound biofilm management seeks more attention. A synthetic peptide with a broad range of antibiofilm activity against preformed and established biofilms, having the ability to kill multispecies bacteria within biofilms and possessing combinatorial activity with other antimicrobial agents, provides significant insights. In this review, we portray the possibilities and difficulties of peptide-mediated treatment in chronic wounds biofilm management and how it can be clinically translated into a product.

Associação entre Vaginose Bacteriana e Anormalidades Citológicas nos Exames Citopatológicos Analisados em um Laboratório Escola de Goiânia-GO / Association Between Bacterial Vaginosis and Cytological Abnormalities in Cytopathological Exams Analyzed in a Laboratory School of Goiânia-GO / Asociación entre Vaginosis Bacteriana y Anormalidades Citológicas en Exámenes Citopatológicos Analizados en una Escuela de Laboratorio de Goiânia-GO

Introdução: A Gardnerella vaginalis facilita a infecção pelo papilomavírus humano (HPV). Objetivo: Verificar a associação entre anormalidades citológicas e presença de Gardnerella vaginalis nos esfregaços cervicovaginais encaminhados ao Laboratório Clínico da Pontifícia Universidade Católica de Goiás (LAC/PUC Goiás) estratificadas por faixa etária. Método: Estudo transversal realizado no LAC/PUC Goiás entre janeiro de 2013 a dezembro de 2015. Para análises estatísticas, a variável idade foi categorizada em ≤39 anos e >40 anos, utilizando o programa IBM SPSS Statistics (Version 2.0, 2011®) para o teste de qui-quadrado (X²), com intervalo de confiança de 95% e valor p<0,05. Resultados: Foram analisados 4.558 exames citopatológicos, a maioria com presença de Lactobacillus spp. (46,97%). A prevalência dos agentes patogênicos foi a Gardnerella vaginalis (79,6%), seguida de Candida spp. (16,8%), Trichomonas vaginalis (2,2%), Herpes simplex (0,4 %) e Chlamydia trachomatis (0,1%). As anormalidades citológicas foram observadas em 9,1%, sendo atypical squamous cells of undetermined significance (ASC-US) 2,57%, low grade squamous intraepithelial lesion (LSIL) 1,78%, atypical squamous cells of undetermined significance cannot exclude high grade squamous intraepithelial lesion (ASC-H) 3,52%, high grade squamous intraepithelial lesion (HSIL) 1,08%, atypical endocervical cells, favor neoplastic (AGC-NEO) 0,22% e carcinoma 0,02%. Houve uma associação significante entre anormalidades citológicas graves e mulheres ≥40 anos, OR 3,01 (IC 95% 2,0-4,58) (p<0,0001). Mulheres ≤40 anos mostraram significância à presença de Gardnerella vaginalis (p<0,0004). Conclusão: Uma elevada prevalência de Gardnerella vaginalis foi encontrada associada com as anormalidades citológicas, principalmente em mulheres sexualmente ativas.

Introduction:Gardnerella vaginalis facilitates human papillomavirus (HPV) infection. Objective: To verify the association between cytological abnormalities and the presence of Gardnerella vaginalis in cervicovaginal smears sent to the Clinical Laboratory of the Pontifical Catholic University of Goiás (LAC/PUC Goiás) stratified by age range. Method: Cross-sectional study carried out at LAC/PUC Goiás from January 2013 to December 2015. For statistical analysis, the variable age was categorized as ≤39 years and >40 years, using the IBM SPSS Statistics program (Version 2.0, 2011®) for the chi-square test (X²), with a 95% confidence interval and p<0.05. Results:4,558 cytopathological exams were analyzed, most of them with the presence of Lactobacillus spp (46.97%). The prevalence of pathogens was Gardnerella vaginalis (79.6%), followed by Candida spp. (16.8%), Trichomonas vaginalis (2.2%), Herpes simplex (0.4%) and Chlamydia trachomatis (0.1%). Cytological abnormalities were observed in 9.1%, being atypical squamous cells of undetermined significance (ASC-US) 2.57%, low grade squamous intraepithelial lesion (LSIL) 1.78%, atypical squamous cells of undetermined significance cannot exclude high intraepithelial lesion (ASC-H) 3.52%, high grade squamous intraepithelial lesion (HSIL) 1.08%, atypical endocervical cells, neoplastic favor (AGC-NEO) 0.22% and carcinoma 0.02%. There was a significant association between severe cytological abnormalities and women >40 years old OR 3.01 (95% CI 2.0-4.58) (p<0.0001). Women ≤40 years old showed the presence of Gardnerella vaginalis (p<0.0004). Conclusion:A high prevalence of Gardnerella vaginalis was found and its association with cytological abnormalities, especially in sexually active women.

Introducción:Gardnerella vaginalis facilita la infección por el virus del papiloma humano (VPH). Objetivo: Verificar la asociación entre anormalidades citológicas y la presencia de Gardnerella vaginalis en frotis cervicovaginales enviadas al Laboratorio Clínico de la Pontificia Universidad Católica de Goiás (LAC/PUC Goiás) estratificadas por grupo de edad. Método: Estudio transversal realizado en LAC/PUC Goiás desde enero de 2013 hasta diciembre de 2015. Para el análisis estadístico, la edad variable se clasificó como ≤39 años y >40 años, utilizando el programa IBM SPSS Statistics (Versión 2.0, 2011®) para la prueba de chi-cuadrado (X²), con un intervalo de confianza del 95% y p <0,05. Resultados: Se analizaron 4.558 exámenes citopatológicos. La prevalencia de Lactobacillusspp. con 46,97%. Los patógenos como Gardnerella vaginalis fueron 79,6%, Candidaspp. 16,8%, Trichomonas vaginalis 2,2%, Herpes simplex 0,4%, y Chlamydia trachomatis 0,1%. Se observaron anormalidades citológicas en 9,1%, con células escamosas atípicas de significado indeterminado (ASC-US) 2,57%, lesión intraepitelial escamosa de bajo grado (LSIL) 1,78%, células escamosas atípicas de significación indeterminada no pueden excluir lesión intraepitelial (ASC-H) 3,52%, lesión intraepitelial escamosa de alto grado (HSIL) 1,08%, células endocervicales atípicas, favor neoplásico (AGC-NEO) 0,22% y carcinoma 0,02%. Hubo una asociación significativa entre anormalidades citológicas severas y mujeres >40 años OR 3,01 (IC 95% 2,0-4,58) (p<0,0001). Las mujeres ≤40 años mostraron la presencia de Gardnerella vaginalis (p<0,0004). Conclusión: Se encontró una alta prevalencia de Gardnerella vaginalis y su asociación con anomalías citológicas, especialmente en mujeres sexualmente activas.

Assessment of the Antibacterial Effects of Bismuth Nanoparticles against Enterococcus faecalis.

INTRODUCTION: Enterococcus faecalis (E. faecalis) is the most important species in dentistry and plays a significant role in the etiology of persistent apical lesions after root canal treatment. Up to date, the intracanal application of 2% chlorhexidine for 7 days is the best way to eliminate E. faecalis. However, due to the ability of this bacterium to persist and survive in harsh environments, many studies have been directed towards finding an alternative strategy for prevention or eradication of it. This study was conducted to investigate the effect of bismuth nanoparticles on E. faecalis, as an etiologic factor in recurrent root canal infections. METHODS: Forty patients, referred to Endodontic Ward of Shiraz University of Medical Science for endodontic pretreatment, provided root canal samples. First, all samples were transferred in Enterococcosel broth and incubated. Then, samples which showed growth were plated on blood agar plates and incubated for further PCR procedure. Nanoparticle powder was dissolved in high-purity water, and the final concentration of bismuth nanoparticles (BiNPs) was measured by the spectrophotometer. Minimum inhibitory concentration (MIC) of BiNPs against E. faecalis was determined by microbroth dilution method according to methods for antimicrobial susceptibility tests. Also, bactericidal assays were conducted in Mueller-Hinton broth medium and reported as the concentration of BiNPs that reduced the viable bacterial count by 99.9%. RESULTS: Of all samples, 77.5% revealed the presence of E. faecalis by PCR. Also, E. faecalis growth inhibition was observed at concentrations ranging from 0.625 µg/ml to 20 µg/ml (geometric mean: 2.337 µg/ml), and the MBC values were between 1.25 µg/ml and 40 µg/ml (geometric mean: 4.781 µg/ml), which in comparison with chlorhexidine, these values were about one-eighth of chlorhexidine. CONCLUSION: The experimental data suggest that bismuth nanoparticles could be an interesting alternative to combat E. faecalis, which, in view of the advantages mentioned for bismuth nanoparticle like inhibiting Streptococcus mutans biofilm formation and higher antibacterial activity compared to chlorhexidine, can be suggested to be used in different fields of dentistry.

A Novel Approach for Detecting Unique Variations among Infectious Bacterial Species in Endocarditic Cardiac Valve Vegetation.

Infectious endocarditis (IE) remains one of the deadliest heart diseases with a high death rate, generally following thrombo-embolic events. Today, therapy is based on surgery and antibiotic therapy. When thromboembolic complications in IE patients persist, this is often due to our lack of knowledge regarding the pathophysiological development and organization of cells in the vegetation, most notably the primordial role of platelets and further triggered hemostasis, which is related to the diversity of infectious microorganisms involved. Our objective was to study the organization of IE vegetations due to different bacteria species in order to understand the related pathophysiological mechanism of vegetation development. We present an approach for ultrastructural analysis of whole-infected heart valve tissue based on scanning electron microscopy and energy-dispersive X-ray spectroscopy. Our approach allowed us to detect differences in cell organization between the analyzed vegetations and revealed a distinct chemical feature in viridans Streptococci ones. Our results illustrate the benefits that such an approach may bring for guiding therapy, considering the germ involved for each IE patient.